jennifer garner. Show her there on the red carpet. She sat down for an interview before her new movie, "dallas buyers clubs." Why her husband, ben affleck, pushed her to take the role. The reason for this study is to determine if it's helping people. Reporter: It takes a certain confidence to play a dowdy doctor. Jennifer garner has got what it takes. They never put makeup on you to make you look like you're not wearing makeup? No. I didn't literally wear makeup. Reporter: "Dallas buyers club" is the real-life story of ron woodruff. He contracts hiv. And is about importing antiviral drugs around the world. You are one of the few movie stars that looks more glamorous in real life than you did in the film. In this film, perhaps. Reporter: A lot has changed since "alias." It's worked less with each baby. And this movie, I wasn't sure i wanted to do it. I was comfortable at home. I liked being at home. My husband really encouraged me to do it. He said, it's time. Reporter: How do you do it with three kids? This? I had a breast pump with me. We shot so quickly. It wasn't a lot of time. Reporter: Speaking of kids, garner and her friend, halle ber berry, just fought for a new law, to get snappers fined and jailed. We're trying to get them to back up and remember that they're our kids. They're real, little kids present. Reporter: Why do people care about seeing your kids in the park? I don't know. I understand why they care. Reporter: You do? Any child you see from when they're born, you watch them grow up. And look how cute she is. I would like my kids' experience of their day-to-day life to change. And I believe that's going to happen. And for that, I thank senator de LEON, AND HALLE BERRY. And "dallas buyers club" opens on friday.

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